texinfo/info/variables.c

   1 /* variables.c -- How to manipulate user visible variables in Info.
   2    $Id: variables.c,v 1.1.1.2 1998/03/22 20:43:01 law Exp $
   3
   4    This file is part of GNU Info, a program for reading online documentation
   5    stored in Info format.
   6
   7    Copyright (C) 1993, 97 Free Software Foundation, Inc.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2, or (at your option)
  12    any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22
  23    Written by Brian Fox (bfox@ai.mit.edu). */
  24
  25 #include "info.h"
  26 #include "variables.h"
  27
  28 /* **************************************************************** */
  29 /*                                                                  */
  30 /*                  User Visible Variables in Info                  */
  31 /*                                                                  */
  32 /* **************************************************************** */
  33
  34 /* Choices used by the completer when reading a zero/non-zero value for
  35    a variable. */
  36 static char *on_off_choices[] = { "Off", "On", (char *)NULL };
  37
  38 VARIABLE_ALIST info_variables[] = {
  39   { "automatic-footnotes",
  40       N_("When \"On\", footnotes appear and disappear automatically"),
  41       &auto_footnotes_p, (char **)on_off_choices },
  42
  43   { "automatic-tiling",
  44       N_("When \"On\", creating or deleting a window resizes other windows"),
  45       &auto_tiling_p, (char **)on_off_choices },
  46
  47   { "visible-bell",
  48       N_("When \"On\", flash the screen instead of ringing the bell"),
  49       &terminal_use_visible_bell_p, (char **)on_off_choices },
  50
  51   { "errors-ring-bell",
  52       N_("When \"On\", errors cause the bell to ring"),
  53       &info_error_rings_bell_p, (char **)on_off_choices },
  54
  55   { "gc-compressed-files",
  56       N_("When \"On\", Info garbage collects files which had to be uncompressed"),
  57       &gc_compressed_files, (char **)on_off_choices },
  58   { "show-index-match",
  59       N_("When \"On\", the portion of the matched search string is highlighted"),
  60       &show_index_match, (char **)on_off_choices },
  61
  62   { "scroll-behaviour",
  63       N_("Controls what happens when scrolling is requested at the end of a node"),
  64       &info_scroll_behaviour, (char **)info_scroll_choices },
  65
  66   { "scroll-step",
  67       N_("The number lines to scroll when the cursor moves out of the window"),
  68       &window_scroll_step, (char **)NULL },
  69
  70   { "ISO-Latin",
  71       N_("When \"On\", Info accepts and displays ISO Latin characters"),
  72       &ISO_Latin_p, (char **)on_off_choices },
  73
  74   { (char *)NULL, (char *)NULL, (int *)NULL, (char **)NULL }
  75 };
  76
  77 DECLARE_INFO_COMMAND (describe_variable, _("Explain the use of a variable"))
  78 {
  79   VARIABLE_ALIST *var;
  80   char *description;
  81
  82   /* Get the variable's name. */
  83   var = read_variable_name (_("Describe variable: "), window);
  84
  85   if (!var)
  86     return;
  87
  88   description = (char *)xmalloc (20 + strlen (var->name)
  89                                  + strlen (_(var->doc)));
  90
  91   if (var->choices)
  92     sprintf (description, "%s (%s): %s.",
  93              var->name, var->choices[*(var->value)], _(var->doc));
  94   else
  95     sprintf (description, "%s (%d): %s.",
  96              var->name, *(var->value), _(var->doc));
  97
  98   window_message_in_echo_area ("%s", description);
  99   free (description);
 100 }
 101
 102 DECLARE_INFO_COMMAND (set_variable, _("Set the value of an Info variable"))
 103 {
 104   VARIABLE_ALIST *var;
 105   char *line;
 106
 107   /* Get the variable's name and value. */
 108   var = read_variable_name (_("Set variable: "), window);
 109
 110   if (!var)
 111     return;
 112
 113   /* Read a new value for this variable. */
 114   {
 115     char prompt[100];
 116
 117     if (!var->choices)
 118       {
 119         int potential_value;
 120
 121         if (info_explicit_arg || count != 1)
 122           potential_value = count;
 123         else
 124           potential_value = *(var->value);
 125
 126         sprintf (prompt, _("Set %s to value (%d): "),
 127                  var->name, potential_value);
 128         line = info_read_in_echo_area (active_window, prompt);
 129
 130         /* If no error was printed, clear the echo area. */
 131         if (!info_error_was_printed)
 132           window_clear_echo_area ();
 133
 134         /* User aborted? */
 135         if (!line)
 136           return;
 137
 138         /* If the user specified a value, get that, otherwise, we are done. */
 139         canonicalize_whitespace (line);
 140         if (*line)
 141           *(var->value) = atoi (line);
 142         else
 143           *(var->value) = potential_value;
 144
 145         free (line);
 146       }
 147     else
 148       {
 149         register int i;
 150         REFERENCE **array = (REFERENCE **)NULL;
 151         int array_index = 0;
 152         int array_slots = 0;
 153
 154         for (i = 0; var->choices[i]; i++)
 155           {
 156             REFERENCE *entry;
 157
 158             entry = (REFERENCE *)xmalloc (sizeof (REFERENCE));
 159             entry->label = xstrdup (var->choices[i]);
 160             entry->nodename = (char *)NULL;
 161             entry->filename = (char *)NULL;
 162
 163             add_pointer_to_array
 164               (entry, array_index, array, array_slots, 10, REFERENCE *);
 165           }
 166
 167         sprintf (prompt, _("Set %s to value (%s): "),
 168                  var->name, var->choices[*(var->value)]);
 169
 170         /* Ask the completer to read a variable value for us. */
 171         line = info_read_completing_in_echo_area (window, prompt, array);
 172
 173         info_free_references (array);
 174
 175         if (!echo_area_is_active)
 176           window_clear_echo_area ();
 177
 178         /* User aborted? */
 179         if (!line)
 180           {
 181             info_abort_key (active_window, 0, 0);
 182             return;
 183           }
 184
 185         /* User accepted default choice?  If so, no change. */
 186         if (!*line)
 187           {
 188             free (line);
 189             return;
 190           }
 191
 192         /* Find the choice in our list of choices. */
 193         for (i = 0; var->choices[i]; i++)
 194           if (strcmp (var->choices[i], line) == 0)
 195             break;
 196
 197         if (var->choices[i])
 198           *(var->value) = i;
 199       }
 200   }
 201 }
 202
 203 /* Read the name of an Info variable in the echo area and return the
 204    address of a VARIABLE_ALIST member.  A return value of NULL indicates
 205    that no variable could be read. */
 206 VARIABLE_ALIST *
 207 read_variable_name (prompt, window)
 208      char *prompt;
 209      WINDOW *window;
 210 {
 211   register int i;
 212   char *line;
 213   REFERENCE **variables;
 214
 215   /* Get the completion array of variable names. */
 216   variables = make_variable_completions_array ();
 217
 218   /* Ask the completer to read a variable for us. */
 219   line =
 220     info_read_completing_in_echo_area (window, prompt, variables);
 221
 222   info_free_references (variables);
 223
 224   if (!echo_area_is_active)
 225     window_clear_echo_area ();
 226
 227   /* User aborted? */
 228   if (!line)
 229     {
 230       info_abort_key (active_window, 0, 0);
 231       return ((VARIABLE_ALIST *)NULL);
 232     }
 233
 234   /* User accepted "default"?  (There is none.) */
 235   if (!*line)
 236     {
 237       free (line);
 238       return ((VARIABLE_ALIST *)NULL);
 239     }
 240
 241   /* Find the variable in our list of variables. */
 242   for (i = 0; info_variables[i].name; i++)
 243     if (strcmp (info_variables[i].name, line) == 0)
 244       break;
 245
 246   if (!info_variables[i].name)
 247     return ((VARIABLE_ALIST *)NULL);
 248   else
 249     return (&(info_variables[i]));
 250 }
 251
 252 /* Make an array of REFERENCE which actually contains the names of the
 253    variables available in Info. */
 254 REFERENCE **
 255 make_variable_completions_array ()
 256 {
 257   register int i;
 258   REFERENCE **array = (REFERENCE **)NULL;
 259   int array_index = 0, array_slots = 0;
 260
 261   for (i = 0; info_variables[i].name; i++)
 262     {
 263       REFERENCE *entry;
 264
 265       entry = (REFERENCE *) xmalloc (sizeof (REFERENCE));
 266       entry->label = xstrdup (info_variables[i].name);
 267       entry->nodename = (char *)NULL;
 268       entry->filename = (char *)NULL;
 269
 270       add_pointer_to_array
 271         (entry, array_index, array, array_slots, 200, REFERENCE *);
 272     }
 273
 274   return (array);
 275 }